Research Cycle

Questions lead to study designs

Epidemiological Study designs

Case Series (Surveillance)

WHO TB Surveillance

Surveillance for Asthma

Results of Surveillance for Asthma

Results of Asthma

Results of Asthma

When is Case Series a Good Strategy?

Time Series Studies

Example of a Time Series Study

Brazil Air Pollution Study

Brazil Air Pollution Study

Methods of the Air Pollution Study

Methods of a Time Series Study

Methods of a Time Series Study

Results of the Air Pollution Study

Results of Air Pollution Study

Results of Air Pollution Study

Graph of the Association between Air Pollution and Mortality

Results of Air Pollution Graph

Results of Air Pollution Graph

Ecological Fallacy

When is Time Series a Good Idea?

Cross sectional Surveys

What is

What is

Features of a Cross Sectional Survey

Example of a Cross-Sectional Survey

Roro Study

Roro Study

Exposure in Roro to Asbestos

Exposure to Asbestos

Exposure to Asbestos

Presentation of Results in a Cross sectional Survey

Presentation of Results Table

Presentation of Results Table

When is a cross-sectional survey a good idea?

When is Cross-sectional survey not a good idea?

Case Control Studies

Conceptual Diagram o Case Control Study

Conceptual Diagram o Case Control Study

Features of Case control studies

Concept of Case Control Study

Condition Cases Controls
Exposed A B
Non-exposed C D

Odds of Exposure among cases = A / C Odds of Exposure among controls = B / D Odds Ratio (OR) is A * D / B * C (Cross Product)

Can you calculate the Odds Ratio?

Condition Cases Controls
Exposed 60 20
Non-exposed 40 80
Total 100 100

Calculation of Odds Ratio

Odds of Exposure Among Cases = 60/40

Odds of Exposure among Controls = 20/80

Odds Ratio = 60 * 80 / 40 * 20 = ??

What is your interpretation?

Example of a Case Control Study

Arsenic Methylation and Bladder Cancer study

Arsenic Methylation and Bladder Cancer study

Result of the Bladder Cancer Case Control Study

Odds ratio of bladder cancer for methylation

Odds ratio of bladder cancer for methylation

How did the risks change with Smoking and Gender

Confounding by Gender and Smoking

Confounding by Gender and Smoking

When is Case Control Study a Good Idea?

Cohort Studies

Conceptual Diagram

Conceptual Diagram

Features of Cohort Studies

Dunedin Longitudinal Study in New Zealand

Dunedin Study

Dunedin Study

Example of An Interesting Cohort Study from Dunedin Cohort

TV viewing

TV viewing

Results of the TV viewing and Health Study

TV view results

TV view results

When is Cohort Study a great idea?

Intervention Research: Randomised Controlled Trials

RCT conceptual

RCT conceptual

Features of Randomised Controlled Trials

Example of an RCT

Methods of an RCT

When is an RCT good idea?

Problems with RCTs

What type of Study to conduct

Evidence Value Graph

Summary